+#define DLSYM(prefix, sym, func) \
+ do { \
+ char _fname[64]; \
+ snprintf(_fname, sizeof(_fname), "%s_%s", prefix, #func); \
+ sym->func = (typeof(sym->func))dlsym(sym->dl_handle, _fname); \
+ } while (0)
+
+/**
+ * Load plugin for a given mount_type from ${pkglibdir}/mount_osd_FSTYPE.so and
+ * return struct of function pointers (will be freed in unloack_backfs_module).
+ *
+ * \param[in] mount_type Mount type to load module for.
+ * \retval Value of backfs_ops struct
+ * \retval NULL if no module exists
+ */
+struct module_backfs_ops *load_backfs_module(enum ldd_mount_type mount_type)
+{
+ void *handle;
+ char *error, filename[512], fsname[512], *name;
+ struct module_backfs_ops *ops;
+
+ /* This deals with duplicate ldd_mount_types resolving to same OSD layer
+ * plugin (e.g. ext3/ldiskfs/ldiskfs2 all being ldiskfs) */
+ strlcpy(fsname, mt_type(mount_type), sizeof(fsname));
+ name = fsname + sizeof("osd-") - 1;
+
+ /* change osd- to osd_ */
+ fsname[sizeof("osd-") - 2] = '_';
+
+ snprintf(filename, sizeof(filename), PLUGIN_DIR"/mount_%s.so", fsname);
+
+ handle = dlopen(filename, RTLD_LAZY);
+
+ /* Check for $LUSTRE environment variable from test-framework.
+ * This allows using locally built modules to be used.
+ */
+ if (handle == NULL) {
+ char *dirname;
+ dirname = getenv("LUSTRE");
+ if (dirname) {
+ snprintf(filename, sizeof(filename),
+ "%s/utils/.libs/mount_%s.so",
+ dirname, fsname);
+ handle = dlopen(filename, RTLD_LAZY);
+ }
+ }
+
+ /* Do not clutter up console with missing types */
+ if (handle == NULL)
+ return NULL;
+
+ ops = malloc(sizeof(*ops));
+ if (ops == NULL) {
+ dlclose(handle);
+ return NULL;
+ }
+
+ ops->dl_handle = handle;
+ dlerror(); /* Clear any existing error */
+
+ DLSYM(name, ops, init);
+ DLSYM(name, ops, fini);
+ DLSYM(name, ops, read_ldd);
+ DLSYM(name, ops, write_ldd);
+ DLSYM(name, ops, is_lustre);
+ DLSYM(name, ops, make_lustre);
+ DLSYM(name, ops, prepare_lustre);
+ DLSYM(name, ops, tune_lustre);
+ DLSYM(name, ops, label_lustre);
+ DLSYM(name, ops, enable_quota);
+
+ error = dlerror();
+ if (error != NULL) {
+ fatal();
+ fprintf(stderr, "%s\n", error);
+ dlclose(handle);
+ free(ops);
+ return NULL;
+ }
+ return ops;
+}
+
+/**
+ * Unload plugin and free backfs_ops structure. Must be called the same number
+ * of times as load_backfs_module is.
+ */
+void unload_backfs_module(struct module_backfs_ops *ops)
+{
+ if (ops == NULL)
+ return;
+
+ dlclose(ops->dl_handle);
+ free(ops);
+}
+
+/* Return true if backfs_ops has operations for the given mount_type. */
+int backfs_mount_type_okay(enum ldd_mount_type mount_type)
+{
+ if (unlikely(mount_type >= LDD_MT_LAST || mount_type < 0)) {
+ fatal();
+ fprintf(stderr, "fs type out of range %d\n", mount_type);
+ return 0;
+ }
+ if (backfs_ops[mount_type] == NULL) {
+ fatal();
+ fprintf(stderr, "unhandled fs type %d '%s'\n",
+ mount_type, mt_str(mount_type));
+ return 0;
+ }
+ return 1;
+}
+
+/* Write the server config files */
+int osd_write_ldd(struct mkfs_opts *mop)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->write_ldd(mop);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+/* Read the server config files */
+int osd_read_ldd(char *dev, struct lustre_disk_data *ldd)
+{
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->read_ldd(dev, ldd);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+/* Was this device formatted for Lustre */
+int osd_is_lustre(char *dev, unsigned *mount_type)
+{
+ int i;
+
+ vprint("checking for existing Lustre data: ");
+
+ for (i = 0; i < LDD_MT_LAST; ++i) {
+ if (backfs_ops[i] != NULL &&
+ backfs_ops[i]->is_lustre(dev, mount_type)) {
+ vprint("found\n");
+ return 1;
+ }
+ }
+
+ vprint("not found\n");
+ return 0;
+}
+
+/* Build fs according to type */
+int osd_make_lustre(struct mkfs_opts *mop)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->make_lustre(mop);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+int osd_prepare_lustre(struct mkfs_opts *mop,
+ char *default_mountopts, int default_len,
+ char *always_mountopts, int always_len)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->prepare_lustre(mop,
+ default_mountopts, default_len,
+ always_mountopts, always_len);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+int osd_tune_lustre(char *dev, struct mount_opts *mop)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->tune_lustre(dev, mop);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+int osd_label_lustre(struct mount_opts *mop)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->label_lustre(mop);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+/* Enable quota accounting */
+int osd_enable_quota(struct mkfs_opts *mop)
+{
+ struct lustre_disk_data *ldd = &mop->mo_ldd;
+ int ret;
+
+ if (backfs_mount_type_okay(ldd->ldd_mount_type))
+ ret = backfs_ops[ldd->ldd_mount_type]->enable_quota(mop);
+
+ else
+ ret = EINVAL;
+
+ return ret;
+}
+
+int osd_init(void)
+{
+ int i, ret = 0;
+
+ for (i = 0; i < LDD_MT_LAST; ++i) {
+ backfs_ops[i] = load_backfs_module(i);
+ if (backfs_ops[i] != NULL)
+ ret = backfs_ops[i]->init();
+ if (ret)
+ break;
+ }
+
+ return ret;
+}
+
+void osd_fini(void)
+{
+ int i;
+
+ for (i = 0; i < LDD_MT_LAST; ++i) {
+ if (backfs_ops[i] != NULL) {
+ backfs_ops[i]->fini();
+ unload_backfs_module(backfs_ops[i]);
+ backfs_ops[i] = NULL;
+ }
+ }
+}
+